The present invention relates to telecommunication controllers (i.e., IC) and, more particularly, voice-switched hands-free radio operation and external intermediate data processing for such controllers.
The cordless telephone industry is currently in a state of expansion and transition. Several cordless telephone system standards have been previously developed. Currently these existing standards collectively require different types of data processing.
Additionally, new system standards for data processing are required by various countries to contend with the expansion of the cordless telephone industry. One standard, Cordless Telephony Generation 2 (CT2) interface specification for digital technology, is currently widely followed in the United Kingdom and certain European countries. The CT2 standard has been accepted by the European Telecommunications Standard Institute (ETSI) as an interim European standard. Unfortunately, not all countries have adopted the same standard. For example, the U.S. follows a standard that is different than the CT2 standard.
Current cordless telephone controllers utilized by the telecommunication industry, such as, for example, Am79C410 controller (i.e., IC) manufactured by Advanced Micro Devices (AMD), perform data processing internally. Since the data processing is internal, the controller must be redesigned each time requirements or standards change so that the data processing complies with the new specifications and standards. Redesign and fabrication of new controllers is expensive and time consuming. Furthermore, fabrication lot sizes must be carefully calculated to avoid creating an excess inventory of outdated controllers.
It would be a distinct advantage to have a controller which is not heavily dependent upon an internal data processing capability. If the controller""s data processing could be upgraded without redesigning and fabricating a new controller, larger quantities of controllers could be manufactured, thereby achieving lower unit costs. Furthermore, the data processing capability of the controller could be upgraded more frequently to meet ever-changing specifications and standards. Providing a controller with a design that is not heavily dependent upon an internal data processing capability eliminates the need to design a new controller for each new data processing implementation. The present invention provides a controller with these advantages.
According to one example embodiment, the invention is directed to a transcoder-codec circuit arrangement that supports voice-switched hands-free radio operation. The circuit arrangement comprises: a first register arranged to store a value indicative of a peak signal in a receive signal path; a first attenuator coupled to the receive path; a second register arranged to store a value indicative of a peak signal in a transmit signal path; a second attenuator coupled to the transmit signal path; a digital signal processor coupled to the first and second registers and configured and arranged to update the value in the first register with a present peak receive signal level if the value in the first register is less than the present peak receive signal level, and arranged to update the value in the second register to a present peak transmit signal level if the value in the second register is less than the present peak transmit signal level; and a microcontroller coupled to the first and second registers and to the first and second attenuators and configured to read values from the first and second register and adjust the first and second attenuators in response to the values.
In another example embodiment, the invention includes a method for supporting voice-switched hands-free radio operation in a transcoder-codec circuit arrangement. The method comprises the steps of: storing in a first register a value indicative of a peak signal in a receive signal path; storing in a second register a value indicative of a peak signal in a transmit signal path; periodically updating the value in the first register with a present peak receive signal level if the value in the first register is less than the present peak receive signal level; periodically updating the value in the second register with a present peak transmit signal level if the value in the second register is less than the present peak transmit signal level; reading values from the first and second registers with the microcontroller and adjusting attenuation levels of signals in the receive signal path and in the transmit signal path in response to values read from the first and second registers.
According to another example embodiment of the present invention, an apparatus is adapted for supporting voice-switched hands-free radio operation in a transcoder-codec circuit arrangement with an intermediate, external digital signal processor according to another embodiment. The apparatus comprises: means for storing a first value indicative of a peak signal in a receive signal path; means for storing a second value indicative of a peak signal in a transmit signal path; means for periodically updating the first value with a present peak receive signal level if the first value is less than the present peak receive signal level; means for periodically updating the second value with a present peak transmit signal level if the second value is less than the present peak transmit signal level; means for reading the first and second values; and means for adjusting attenuation levels of signals in the receive signal path and in the transmit signal path in response to the read first and second values.
The above summary of the present invention is not intended to describe each illustrated embodiment or every implementation of the present invention. The figures in the detailed description which follow more particularly exemplify these embodiments.